DSC-Merging the Alarm Events Generated

[Vijay Jayabalan]

I am afraid whether I will be able to merge the alarm events generated in two different database configured in two PC’s (Servers).

Both the data base monitors same traces and processes, one pc will be an active server and another will be an backup server. We have situation that one server may fail and come back alive.  In this situation how can I combine the alarm events generated in two different PC's?

Merging the database doesn’t helps instead generates the error when queried for logged Alarms and Events. However merging the data base combines the traces data.

We are using Labview 8.2.1 and DSC 8.2.

Any help will be much appriciated.

Thanks,

Vijay Jayabalan.

[jpaul]

Vijay,

In order to merge your alarms, could you develop a LabVIEW application which calls the Alarm & Event Query VI for each database. This will return all of the alarms and allow you then to merge the array of strings together. Would this work in your situation or are  you trying to merge the alarms within the Citadel database?

Cheers,

Jonah
Applications Engineer
National Instruments

[Vijay Jayabalan]

Thanks for your reply

We are monitoring about 25000+ I/O points (cFP-180X), we are using Shared Variable in order to read data from cFP and update the data for Shared Variable deployed on Two Central Server Computer (One Duty and other standby named A and B servers respectively) each hosting a separate set of shared variable for the I/O points (only difference being the computer names)

The Set of shared variable deployed on both servers, have the same configuration information such as alarms, logging etc as well as the same names.
Given a situation that Server A fails (PC Crash/shutdown/restart), then the other server B will still provide the Alarms and Event information.
However, when Server A return to normal operation then the Alarm and Event Set Time, Acknowledgement Time and Clear Time will be different than that in Server B.

With an example let us say that,

At 4.00 am in the morning Server A works fine and Server B is down, now the Shared Variable Deployed in the Server A will read data from the Field and Update any alarm information, if an alarm occurs (Shared Variable) at 4 am then this information of Set Time of Alarm (Read Alarm VI) is present in Server A and not in Shared Variable deployed Server B.

Now, on the same day let us say Server B start working normally at 11.00 am, so the (Read Alarm VI) from the Shared Variable deployed in Server B will return the Set Time of the alarm as 11 am and not as 4 am (which is when the alarm actually occurred)

What we would like to know is there any way we could merge the alarm information between both the computers for two sets of Shared Variables (similar to Redundancy in Lookout)?

Kindly reply in case you need more details.

[jpaul]

Hi Vijay,

The best option for you would be to archive the alarms, which merges the alarms, either into one of the two databases or both of them into a temporary directory. There is a Alarm & Event Archive.vi that allows you to do this merging process (see attached VI). The VI also has options to select which shared variables to archive and timestamp ranges. Please explore this option and let me know if you have any further questions regarding the issue.

Cheers,

Jonah
Applications Engineer
National Instruments